Method and service kit for revitalizing shock absorbers

ABSTRACT

A method and kit accessories useful in extending the service life of a permanently assembled shock absorber. The kit includes a boring tool, one or more self-tapping plugs and a container of sufficient fluid to replace the original fluid charge and having a viscosity effective to substantially restore the original operating characteristics of the shock absorber. The invention also includes a permanently assembled shock absorber revitalized without need for disassembly.

e I United States Patent 1 [1 1 3,751,786 Lyon Aug. 14, 1973 METHOD AND SERVICE KIT FOR 1,492,332 4/1924 Lang 188/313 REVITALIZING SHOCK ABSORBERS 2,348,160 5/1944 Thornhill 188/317 [76] Inventor: Thomas R. Lyon, 521 Terrado Dr., OTHER CA S Monrovia, Calif- 91016 l-leldt, P. M., The Automotive Chassis, 1948, P. M. 22 Filed; Sept. 3 19 9 Heldt, Nyack, N.Y., Page 524, Lines 2-5.

Dylce, A. L., Dyke's Automobile Encyclopedia, 1936, [2]] Appl' 854868 Goodheart-Wi11cox Co., Chicago, 111., Page 12, Lines 43-44. [52] U.S. Cl. 29/401, 188/311 Church, A. 11., Mechanical Vibrations, John Wiley and [51] Int. Cl B23p 7/00 Sons, Inc., New York, N.Y., 1967, page 70, Lines l-4. [58] Field of Search 29/401, 402, 436;

141/329, Primary Examiner-Charles W. Lanham 280/1065 R, 106.5 A; 137/315, 319, 327, 15; Assistant Examiner c Crane 65 Attorney-Sellers and Brace 5 6 UNlTE l z'i l S l lENTs [57 ABS CT 61 594 9 898 A method and kit accessories useful in extending the /1 service life of a permanently assembled shock ab- 2,092,259 9/1937 3,059,269 10/1962 sorber. The kit includes a boring tool, one or more self- 3,139,159 6/1964 tapping plugs and a container of sufficlentfluid to re- 3,l97,19l 7/1965 place the original fluid charge and having a viscosity 3,557,435 1/ 1971 effective to substantially restore the original operating 3,521,464 7/1970 characteristics of the shock absorber. The invention 2,133,003 1939 also includes a permanently assembled shock absorber 1,831,136 11/1931 revitalized without need for disassembly. 2,117,837 5/1938 2,333,096 11/1943 6 Claims, 4 Drawing Figures PAIENTEDAUB 14 1915 INVENTOR 7/70 14/4 5 1e 4 V0/\/ METHOD AND SERVICE KIT FOR REVITALIZING SHOCK ABSORBERS This invention relates to shock absorbers, and more particularly to means for and a method of processing used permanently assembled shock absorbers in a simple, inexpensive manner to restore their operating effectiveness.

Many shock absorbers, particularly those in common use on motor vehicles, are permanently assembled at the time of manufacture. For this reason, it is not feasible to replace worn and unserviceable parts making it necessary to replace an unserviceable shock absorber with a new one.

By this invention there is provided a simple, inexpensive highly effective technique for extending the service life of worn shock absorbers suitable for practice by mechanics, service stations and vehicle owners following simple instructions and using readily-available simple tools. The service kit proper includes a boring tool, a new charge of fluid adequate for recharging the shock absorber and suitable means for replugging holes made by a drill furnished with the kit to drain the original fluid from the assemblies. A sealed container of fresh fluid is preferably provided with a spout to facilitate transfer of the fluid into the shock absorber.

Accordingly it is a primary object of the present invention to provide a simple, highly effective method for reconditioning permanently assembled shock absorbers to extend the service life thereof.

Another object of the invention is the provision of a single use service kit for use in revitalizing a worn shock absorber.

Another object of the invention is the provision of a unique method of servicing and revitalizing permanently assembled shock absorbers without need for disassembly or replacing any component.

These and other more specific objects will appear upon reading the following specification and claims and upon considering in connection therewith the attached drawing to which they relate.

Referring now to the drawing in which a preferred embodiment of the invention is illustrated:

FIG. 1 is a side view of a typical permanently assembled shock absorber after being reconditioned in accordance with the principles of this invention;

FIG. 2 is an enlarged fragmentary view partly in section of the shock absorber and showing one of the service kit plugs removed;

FIG. 3 is a fragmentary view with a portion of the outer housing broken away and showing the assembly being recharged with fluid; and

FIG. 4 is a view of the tool used to form the drain holes.

Referring more particularly to FIG. 1, there is shown a conventional permanently assembled shock absorber, designated generally 10, having a tubular main body 11. Secured to one end of this body is a coupling member 12 for use in pivotally connecting the shock absorber to a chassis axle assembly. Reciprocally supported in the upper end of main housing 11 is a piston rod 14 also provided at its outer end with a mounting coupling 15 connectable to the main frame of the chassis in knownmanner. A tubular dust guard 16 has its closed end fixed to coupling 15 and rod 14 and reciprocates with the latter loosely about the upper end of main housing 11.

The internal structural details of the shock absorber are not material to this invention and may be of any well known type. Those shown in FIG. 2 are typical, the main body tube 11 serving as a fluid reservoir enclosing the main cylinder 18 of the shock absorber and suitably supported concentrically of housing ill. The right hand end of cylinder l8 will be understood as having a suit able fluid seal means as is true respecting end cover 19 of reservoir Ill.

Secured to the inner end of piston rod 14 is any suitable piston and valve assembly, designated generally 23. This piston is held slidably supported on the shouldered stem 24 of the piston rod by a nut 25. Piston 26 is encircled by a suitable sealing ring 26' and its bottom is provided with two rings of small ports 27,28, the smaller ring 28 being normally closed by a disc valve 29 and a compression spring 30 encircling the piston rod. The larger diameter ring of ports 27 is normally held closed by a spider valve 32 and a bowed disc spring 33 also effective to hold the perforated disc 34 seated against the shouldered end of stem 24.

Suitably supported in the lower end of cylinder 18 is a second valve assembly 38. This assembly includes a mounting ring 39 sealed across the end of cylinder 18 and supporting a cup-shaped valve member 41 normally held against seat ring 42 by a spider type disc spring 43. A poppet valve 45 is normally held seated across the port in the bottom of valve 4] by spring 46. Valve 38 serves to control the flow of fluid between the shock absorber reservoir 48 and the interior of the main cylinder 18. The operation of the two valve assemblies 23, and 38 need not be described since they are well known to persons skilled in this art.

To revitalize a worn shock absorber, the user detaches assembly 10 from the vehicle and utilizes the tool 50 to drill or pierce a pair of holes 51,52 along one side near the opposite ends of reservoir casing 11. The original fluid charge of the absorber is then drained from openings 51,52 while reciprocating piston rod I4 as draining proceeds to facilitate drainage of the'fluid present in the cylinder 10 to either side of piston 23. Once the operator is assured substantially all of the old fluid has been drained, the tip of spout 53 of a plastic container 54 is cut off. This container carries sufficient fluid to recharge at least one and preferably all four shock absorbers of a single vehicle. It is important that the viscosity of the new fluid charge be substantially greater than the viscosity of the original fluid charge. The particular viscosity rating will be understood as varying slightly for different shock absorber constructions and should be selected to compensate for normal wear experienced by a particular absorber construction after a designated usage, as 10,000 miles. Nozzle 53 of container 54 is sized to fit readily into one of the openings 51 and 52, the displaced air present being vented to the atmosphere through the other opening. During the charging operation, piston rod 114 is operated to and fro to aid in distributing the charge interiorly of cylinder l8. Either of the ports 51,52 may be used as the charging port and the other as a vent.

It will be understood that fluid container 54 is preferably transparent or semi-transparent and provided with level marks distributed along its side to indicate when the proper proportion of its contents has been charged into each of the shock assemblies of a vehicle. Altematively, separate containers of fluid adequate for each of the four shock absorbers may be provided so that the user merely dispenses the entire contents of one container in to each of the shock assemblies.

After the new fluid charge has been introduced, openings 51,52 are closed by self-tapping screws each provided with a sealing gasket 56. The assemblies are now ready for reassembly to the vehicle and will function substantially with the same effectiveness and efficiency as when new owing to the new timing characteristics imparted to the absorber by its higher viscosity fluid charge.

While the particular method and service kit for revitalizing shock absorbers herein shown and disclosed in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention.

l claim:

1. That method of reconditioning a worn nonrechargeable shock absorber to extend the effective serviceability thereof which comprises: forming a port into the interior of the shock absorber in an area in communication with the fluid charge therein, modifying the viscosity of said fluid charge by introducing into the shock absorber through said port an adequate quantity of fluid of substantially greater viscosity than the viscosity of the original fluid charge to substantially restore the operating characteristics of said shock absorber, and closing said port.

2. That method defined in claim 1 characterized in the step of draining at least a portion of the fluid from said shock absorber through said port before introducing fluid of higher viscosity and reclosing said port.

3. That method defined in claim 2 characterized in the step of charging said shock absorber with said higher viscosity fluid via the same port through which fluid was withdrawn.

4. That method defined in claim 2 characterized in the step of opening said port by piercing an opening through the wall of the shock absorber, and closing said opening in a fluid tight manner after recharging the shock absorber with said higher viscosity fluid.

5. That method defined in claim 2 characterized in the step of closing said port with a self-tapping screw equipped with a sealing gasket.

6. That method defined in claim 1 characterized in fonning separate ports through the sidewall of said shock absorber to expedite withdrawal of at least a portion of the existing fluid charge therefrom, charging said shock absorber with said higher viscosity fluid charge, and sealing said ports closed. 

1. That method of reconditioning a worn non-rechargeable shock absorber to extend the effective serviceability thereof which comprises: forming a port into the interior of the shock absorber in an area in communication with the fluid charge therein, modifying the viscosity of said fluid charge by introducing into the shock absorber through said port an adequate quantity of fluid of substantially greater viscosity than the viscosity of the original fluid charge to substantially restore the operating characteristics of said shock absorber, and closing said port.
 2. That method defined in claim 1 characterized in the step of draining at least a portion of the fluid from said shock absorber through said port before introducing fluid of higher viscosity and reclosing said port.
 3. That method defined in claim 2 characterized in the step of charging said shock absorber with said higher viscosity fluid via the same port through which fluid was withdrawn.
 4. That method defined in claim 2 characterized in the step of opening said port by piercing an opening through the wall of the shock absorber, and closing said opening in a fluid tight manner after recharging the shock absorber with said higher viscosity fluid.
 5. That method defined in claim 2 characterized in the step of closing said port with a self-tapping screw equipped with a sealing gasket.
 6. That method defined in claim 1 characterized in forming separate ports through the sidewall of said shock absorber to expedite withdrawal of at least a portion of the existing fluid charge therefrom, charging said shock absorber with said higher viscosity fluid charge, and sealing said ports closed. 